Best Price Guarantee Program

Changer is implementing the Lowest Price Guarantee Program; when the price of other DEX Aggregators such as 1inch and Matcha is better than Changer, we compensate for the price gap with 2x changer tokens (ecoCNG).
Token Reward Allocation 
The lowest price guarantee program operates for a duration of 90 days from January 12, 2022 at 3:00 am (UTC). A total of 2 million ecoCNG tokens are allocated to the initial Lowest Price Guarantee Program. There are 22,222 (= 90/2,000,000) ecoCNG tokens available per day on a first-come, first-served basis. Once the limited stock is exhausted the reward will no longer be provided.
Reward Payment Method 
Compensation rewards are automatically credited after the transaction. Customers can check their accumulated rewards and claim them at any time. (Gas fee will not be compensated)
Unspent Rewards 
If the daily Compensation reward allocation hasn't been exhausted, the remaining amount is to be carried over to the next day. If only 10,000 tokens have been exhausted on Monday, the leftover tokens will be allocated to the following day, and the total available rewards would sum up to 34,444 tokens. (22,222+12,222) Remaining tokens after the 90 day program will be returned to the Changer Treasury to be used for other promotions. After the 90-day first difference compensation program operation, another compensation program will start after reviews and analysis.
​​Reward Limit per Transaction 
There is not a compensation limit per wallet, but the maximum compensation limit per transaction is limited to 2,000 ecoCNG. If the difference from 1 inch is $1,000 and the price per CNG is $0.5, you should receive $1,000x2/$0.5 = 4,000 ecoCNG, but only 2,000 ecoCNG will be credited as the reward limit per transaction is limited to 2,000 ecoCNG. Even though you are entitled to receive 2,000 ecoCNG, if 21,222 ecoCNG out of the 22,222 ecoCNG prepared for the day have already been exhausted, only 1,000 ecoCNG, the remaining quantity for the day, will be accumulated to your account.
Rewarded Trading Pairs 
For coins with low trading volume, the difference in slippage for each DEX is large and liquidity is unstable, making it difficult to compensate. Accordingly, Changer selected the top 25 most traded trading pairs in the last month on major DEXs such as Uniswap, Sushiswap, and Curve.
Trading pairs that include WETH will be treated equally as ETH pairs guaranteeing the lowest price. For example, both WETH-USDC and ETH-USDC are pairs guaranteed on Changer and will receive rewards. 
All trading pairs are guaranteed bidirectionally. That is, if the USDT-USDC pair is guaranteed, USDC-USDT pair is guaranteed as well and qualifiable for rewards.
Best Price Guarantee Program (Bidirectional)
WETH-USDC
WETH-USDT
WETH-DAI
USDT-USDC
WETH-WBTC
USDC-FEI
DAI-USDC
WETH-MATIC
USDC-UST
WBTC-USDC
DAI-OHM
WETH-OHM
WETH-SPELL
CVX-WETH
SUSHI-WETH
CRV-WETH
WBTC-WETH
MIM-USDT
MIM-USDC
LUSD-DAI
Price Gap Calculating Criteria
The price gap is calculated as below:
1.When the price gap is less than 3%, 2) compensate twice the price gap from the other service with the largest price gap with the ecoCNG token
Although we currently compensate for the price gap only with 1 inch and Matcha, the two most widely known aggregators, price comparisons with other aggregators will be added in the future.
The reason for compensating only for cases where the price gap is less than 3% range is that sometimes it shows abnormal order book although it is impossible to execute an actual transaction.
To avoid the problem of having to compensate for the price gap based on the error, which is difficult to actually execute the transaction, Changer thought it would be reasonable to compensate only for transactions with the price gap of 3% or less.
 In almost all normal situations, the price gap between Changer and other DEX aggregators does not differ by more than 3%. In that case, it is likely to be an error in other Services’ API.
Price Guarantee Case
1) Price difference within 3% 
If the price of 1 ETH is $4,000 on Changer and $3,999/$3,998 on 1inch and Matcha respectively, Changer will double the gap ($2) between us and Matcha, which is the largest difference, and reimburse $4 worth ecoCNG after the transaction.
2) Price difference over 3%
If the price of 1 ETH is $4,000 on Changer and $3,500/$3,980 on 1inch and Matcha respectively, You may think you will get $1,000 worth of ecoCNG, which is 2 times the $500 price difference between 1inch and Changer.
However, it is theoretically impossible for 1ETH to be $3,500 for 1inch when the current price is $4,000 and $3,980 for Changer and Matcha respectively. It would not be executed if you try to make an actual transaction for this 12.5% price gap.
There may be various reasons for this error, such as temporary API problems of other DEX aggregators.
Therefore, Changer will reimburse $40 worth of ecoCNG, 2 times the price difference with Matcha ($20), which is the largest price gap within the 3% range, after the transaction.
Gas Fee Protection
Some trades might qualify for rewards, but the estimated gas fee to collect and accumulate the rewards might be greater than the rewards itself.
In such a case, the compensation reward will not be accumulated nor require an additional gas fee to collect the rewards.
Other Reward Programs
In addition to the Price guarantee program, Changer is preparing a variety of reward programs including the rewards for affiliated wallet users, transaction promotion, and rewards for the CNG stakers. The reward programs will be released soon.
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